Asteroid 2867 Steins

Fig. 12.10 . The Rosetta spacecraft flew by the main-belt asteroid 2867 Steins on 5 September 2005, capturing this sequence of images, the first of a relatively rare E-type asteroid. A chain of craters runs vertically across the bottom parts of the asteroid, while a large crater with a diameter of 2.1 kilometers dominates the northern top. Asteroid 2867 Steins is an oblate body resembling a cut diamond, with an effective spherical diameter of 5.3 kilometers, and a surface that reflects about 35 percent of the incident sunlight. Crater counts indicate a distinct lack of small craters. Landslides of loosely bound material may have covered numerous small craters and filled in shallow ones. The asteroid is not solid rock but a rubble pile whose conical appearance may be the result of reshaping due to the radiation of incident light as infrared emission, which carries off momentum as well as heat. Rosetta is expected to fly by asteroid 21 Lucetia in July 2010 and to land on comet Churyumov-Gerasimenko in November 2014. (Courtesy of ESA/Rosetta team.)